apps/include/dma.h

   1 /*
   2     meinOS - A unix-like x86 microkernel operating system
   3     Copyright (C) 2008  Janosch Gräf <janosch.graef@gmx.net>
   4
   5     This program is free software: you can redistribute it and/or modify
   6     it under the terms of the GNU Lesser General Public License as published by
   7     the Free Software Foundation, either version 3 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU Lesser General Public License for more details.
  14
  15     You should have received a copy of the GNU Lesser General Public License
  16     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19 #ifndef _DMA_H_
  20 #define _DMA_H_
  21
  22 #include <sys/types.h>
  23 #include <rpc.h>
  24 #include <misc.h>
  25 #include <limits.h>
  26 #include <syscall.h>
  27
  28 #define DMA_PAGE_SIZE PAGE_SIZE
  29 #define DMA_MAXCOUNT  65536
  30
  31 // Device => Memory
  32 #define DMA_MODE_READ           (1 << 2)
  33 // Memory => Device
  34 #define DMA_MODE_WRITE          (2 << 2)
  35 #define DMA_MODE_ON_DEMAND      (0 << 6)
  36 #define DMA_MODE_SINGLE         (1 << 6)
  37 #define DMA_MODE_BLOCK          (2 << 6)
  38
  39 /**
  40  * Allocates DMA memory
  41  *  @param size Size of DMA memory
  42  *  @return DMA memory
  43  */
  44 static inline void *dma_alloc(size_t size) {
  45   return (void*)syscall_call(SYSCALL_MEM_DMA_ALLOC,1,((size-1)/DMA_PAGE_SIZE+1)*DMA_PAGE_SIZE);
  46 }
  47
  48 /**
  49  * Frees DMA memory
  50  *  @param buffer DMA memory
  51  *  @param size Size of DMA memory
  52  *  @return Success?
  53  */
  54 static inline int dma_free(void *buffer,size_t size) {
  55   return syscall_call(SYSCALL_MEM_DMA_FREE,2,buffer,((size-1)/DMA_PAGE_SIZE+1)*DMA_PAGE_SIZE);
  56 }
  57
  58 /**
  59  * Checks if DMA channel is ready to use
  60  *  @param channel DMA channel
  61  *  @return If channel is ready to use
  62  */
  63 static inline int dma_isready(channel) {
  64   return rpc_call("dma_isready",0,channel);
  65 }
  66
  67 /**
  68  * Start a DMA transfer
  69  *  @param channel DMA channel
  70  *  @param buf Buffer to read/write data from/to
  71  *  @param count How many bytes to transfer
  72  *  @param mode Transfer mode
  73  *  @return Success?
  74  */
  75 static inline int dma_start(int channel,void *buf,size_t count,int mode) {
  76   return rpc_call("dma_start",0,channel,mem_getphysaddr(buf),count,mode);
  77 }
  78
  79 /**
  80  * Stops a DMA transfer
  81  *  @param channel DMA channel
  82  *  @return Success?
  83  */
  84 static inline int dma_stop(int channel) {
  85   return rpc_call("dma_stop",0,channel);
  86 }
  87
  88 #endif